The Influence of Volcanism, Soils, and Climate in the Endemicity Levels of Asteraceae in the Arequipa Region (Southern Peru)

We present the diversity of Asteraceae in the Arequipa Region of southern Peru, an area strongly influenced by volcanism, which has given rise to different soil types and has determined a very wide bioclimatic and vegetational zonation. We present the distribution of Asteraceae endemisms of Peru and Arequipa, and of the dry puna. For this purpose, we have used the bioclimatic methodology of Rivas-Martínez, the characteristic soils of each collection point, and the distance of the collection localities from the volcanoes. In the Arequipa Region, we found 232 species of Asteraceae, of which 49 are endemic to Peru or to the dry puna and 7 are endemic to the studied area. Of these endemics, 10 are thermotropical, 1 is mesotropical, 3 are supratropical, and 3 are orotropical bioindicators, being mainly distributed in two large groups of soils: sandy and saline or gypsiferous soils, mostly located within the thermotropical belt of the coastal desert, and andosols and cambisols distributed from the thermotropical to the cryorotropical belts of the Andes. The greatest number of endemics and semi-endemics are found in the vicinity of the arc formed by the Misti, Chachani and Pichu-Pichu volcanoes.

Pollen preferences of stingless bees in the Amazon region and southern highlands of Ecuador by scanning electron microscopy and morphometry

Stingless bees are effective pollinators of native tropical flora. Their environmental service maintains flow of pollen through pollination, increase reproductive success and influence genetic structure in plants. The management of stingless bees “meliponiculture”, is an activity limited to the countryside in Ecuador. The lack of knowledge of their managers about pollen resources can affect the correct maintenance/production of nests. The objective is to identify botanical families and genera of pollen grains collected by stingless bees by morphological features and differentiate potential species using geometric morphometry. Thirty-six pot pollen samples were collected from three Ecuadorian provinces located in two climatically different zones. Pollen type identification was based on the Number, Position, Character system. Using morphological features, the families and genera were established. Morphometry landmarks were used to show variation for species differentiation. Abundance, diversity, similarity and dominance indices were established by counting pollen grains, as well as spatial distribution relationships by means of Poisson regression. Forty-six pollen types were determined in two study areas, classified into 27 families and 18 genera. In addition, it was possible to identify more than one species, classified within the same family and genus, thanks to morphometric analysis. 1148 ± 799 (max 4211; min 29) pollen grains were counting in average. The diversity showed a high richness, low dominance and similarity between pollen resources. Families Melastomataceae and Asteraceae, genera Miconia and Bidens, were found as the main pollen resources. The stingless bee of this study are mostly generalist as shown the interaction network. The results of the present survey showed that stingless bees do not collect pollen from a single species, although there is evidence of a predilection for certain plant families. The diversity indexes showed high richness but low uniformity in the abundance of each family identified. The results of the study are also meaningful to the meliponiculture sector as there is a need to improve management practices to preserve the biodiversity and the environment.

Biogeographic and metabolic studies support a glacial radiation hypothesis during Chrysanthemum evolution

Chrysanthemum (Chrysanthemum morifolium Ramat.) is an economically important plant species growing worldwide. However, its origin, especially as revealed by biogeographic and metabolomics research, remains unclear. To understand the geographic distribution of species diversity and metabolomics in three genera (Chrysanthemum, Ajania, and Phaeostigma), geographic information systems and gas chromatography-mass spectrometry were used in 19, 15, and 4 species respectively. China and Japan were two potential panbiogeographic nodes and diverse hotspots of Chrysanthemum, with species richness ratios of 58.97 and 33.33%. We studied different species from two hotspots which in similar geographical environments had closer chemotaxonomic relationships under the same cultivation conditions based on a cluster of 30 secondary metabolites. The average distribution altitude (ADA) differed significantly among Chrysanthemum, Ajania, and Phaeostigma in which it was 1227.49, 2400.12, and 3760.53 m.a.s.l. respectively, and the presence/absence of ray florets (RF) was significantly correlated with ADA (-0.62). Mountain landform was an important contributor to global Chrysanthemum diversity, playing a key role in the divergence and distribution pattern of Chrysanthemum and its allies. The Hengduan Mountains-Qinling Mountains (HDQ) in China was a potential secondary radiation and evolution center of Chrysanthemum and its related genera in the world. During the Quaternary glacial-interglacial cycles, this region became their refuge, and they radiated and evolved from this center.

Valerianapraecipitis (Caprifoliaceae), a species new to science and endemic to Central Chile

The species Valerianapraecipitis (Caprifoliaceae), new to science and endemic to the Ñuble Region, Central Chile, is formally described. Morphological data support its placement in a new species, clearly different from V.philippiana. A detailed description, insights about its habitat and ecology, distribution map and illustration are provided. A table of comparison is also given with the morphological characters discriminating V.praecipitis from V.philippiana. The species is assessed as Endangered (EN) under the IUCN categories.

Application of multimicroscopic techniques (LM and SEM) in comparative palynological study of Asteroideae members, inhabited in Pakistan

In the present study light and scanning electron microscopic approaches were used to study the palynological variations among 30 Asteroideae members. Variety of qualitative and quantitative palynological characters like pollen shape and type, pollen sculpturing, pollen size, P/E ratio, exine and intine thickness, interspecific difference, colpi size, pore size, spines length, spine width, and pollen fertility were observed. Results reported remarkable variations among pollen characters of studied taxa. The shape of pollen grains in polar and equatorial views varied from specie to specie such as spheroidal, prolate, oblate, subspheroidal, oblate spheroidal, prolate spheroidal, suboblate, and sub prolate. Bidens pilosa L. showed maximum pollen size in both polar and equatorial views, whereas minimum pollen size in polar view was found in Tetraneuris scaposa (DC.) Greene. (i.e., 30.5 μm) and in equatorial view was found in Cosmos sulphureus Cav. (25.5 μm).The highest P/E ratio (1.39 μm) was measured in Glebionis coronaria L. The values of exine and intine thickness also varied. Tricolporate, tetracolporate, trizonocolporate, pentoporate, and polypentoporate pollen types were examined. Spinateand echinate pollen sculpturingobserved under SEM. Variations in spine length and width also recorded. The maximum pollen fertility (98%) was measured in Chrysanthemum morifolium Ramat. and the lowest (56%) was recorded in Thymophylla tenuiloba (DC.) Small. It was concluded that the variations in qualitative and quantitative characters were seemed to be valuable for the taxonomic investigations of Asteroideae taxa.

Scanning electron microscopic screening of 20 medicinally important Asteroideae taxa

In the present study anatomical characterization of 20 medicinally important Asteroideae species were done under light and scanning electron microscopy. Variety of qualitative and quantitative anatomical characters like epidermal cells, stomata, guard cells, subsidiary cells, trichomes and oil droplets were observed. Generally pentagonal, polygonal, irregular or hexagonal, smooth, undulating thick walled epidermal cells were observed in studied species. In abaxial surface Thymophylla tenuiloba L. possessed the largest length of epidermal cell that is, 221.6 (156.6-286.6) μm whereas Bellis perenis L. showed the smallest length that is, 46.4 (32.6-60.2) μm. Average width of epidermal cells ranged from 57 (22-92) μm to 169 (127.9-210.1) μm. Cosmos sulphureus Cav. had smallest width while Thymophylla tenuiloba L. had the largest width. In adaxial surface Artemisia absinthium L. possessed the largest length of epidermal cell that is, 269 (165.1-372.9) μm whereas Bellis perenis L. showed the smallest length that is, 61.4 (42.6-80.2) μm. Average width of epidermal cells ranged from 50.8 (32.6-69) μm to 260 (116-202) μm. Thymophylla tenuiloba L. had smallest width while Dahlia pinnata Cav. had the largest width. Among stomatal characters anisocytic, anomocytic, and diacytic stomata were observed in selected species of Asteroideae. Nonglandular uniserate, multicellular, unbranched pointed tips with bulbous base trichomes were reported in some Asteroideae members while some possessed glandular, capitates mushroom like multicellular trichomes covered with tubercle papicles. Rounded, oval, triangular shaped oil droplets were observed in some species. It is concluded that qualitative and qualitative anatomical variations in trichomes, stomata and epidermal cells are of good taxonomic value for the Asteroideae species.

A plant from the altiplano of Northern Chile Senecio nutans, inhibits the Vibrio cholerae pathogen

BACKGROUND

In the altiplano of Northern Chile the plant Senecio nutans is habitually used as an infusion to relieve the effects of altitude sickness (locally known as "puna"). It is also used to alleviate the bronchitis, whooping cough, asthma, stomachache, tiredness and fever. The extreme conditions under which these plant grow and scientific data that shows the inhibiting potential of the essential oils of plants of the genus Senecio represents great potential in the study of their application to control pathogens like Vibrio Cholera.

METHODS

The essential oil from aerial parts of S. nutans was isolated by hydrodistillation and the chemical composition characterized by GC-MS analyses. The antibacterial potential and determination of MIC value, was estimated in both micro and macro dilution method.

RESULTS

The GC-MS analysis of essential oil of S. nutans showed the presence of methyl cinnamate (44.9 %), p-cymenol (27.2 %), and terpinen-4-ol (6.8 %), α-terpineol (4.1 %), t-cadinol (3.5 %), methyl hydrocinnamate (2.1 %), δ-cadinene (2.0 %), p-cymene (1.9 %), γ-terpinene (1.8 %), α-cadinol (1.6 %), cis-sabinene hydrate (1.1 %), caryophyllene (0.9 %), β-pinene (0.8 %), and α-terpinene (0.6 %) as major components. Moreover, the oil of S. nutans exhibited an important antibacterial activity with a diameter of inhibition zone growth of 22 mm and the MIC value of 0.4 mg/mL against pathogenic bacteria V. cholerae.

CONCLUSIONS

The results show for the first time the antibacterial activity of the essential oils of S. nutans against the V. cholerae pathogen, an activity that can be applied as a preventive treatment against the action of pathogen.

Synopsis of Plazia Ruiz & Pav. (Onoserideae, Asteraceae), including a new species from northern Peru

A synopsis of Plazia Ruiz & Pav. (Onoserideae, Asteraceae) is presented, including the description of a new species, Plazia robinsonii M.O.Dillon & Sagást., from a locality c. 20 kms west of Huamachuco, Department of La Libertad in northern Peru. It most closely resembles Plazia conferta Ruiz & Pav., a narrow endemic from central Peru some 450 km to the south; however, the latter species has larger leaves and smaller capitula. Plazia is a small genus of four species confined to the Andean Cordillera of Peru, Bolivia, Chile, and Argentina. A distribution map of the four species, an illustration of the new species, a photograph of the holotype, and a key to species are provided.